1. Field of the Invention
The present invention relates to an optical connecting device to be used in the field of an optical communication.
2. Description of the Related Art
A conventional optical branching coupler has the structure as shown in FIG. 1. In the drawing, reference numeral 10 denotes an optical waveguide chip. An optical branch coupling wave guide 11 is formed in the optical waveguide chip 10. The optical branch coupling wave guide 11 comprises an optical wave guides 11a and 11b. The optical wave guides 11a and 11b are formed to be made close to each other at a central part of the optical waveguide chip 10. Optical fibers 12a to 12d are optically connected to the end portion of the optical branch coupling wave guide 11. In this case, a length L, which is made both wave guides close to each other, is determined by what degree the optical wave guides 11a and 11b are made close to each other and a wavelength of an optical signal. Thereby, for example, a distribution rate, that is, what degree the optical signal to be inputted from the optical fiber 12a is distributed to optical fibers 12c and 12d, is determined. Therefore, the optical branching couplers having various distribution rates can be designed by changing the degree of how much the optical wave guides are made close to each other and the length L. In conventional, for example, the optical fibers 12a and 12b in the input side are provided at the same transmitting location by an optical fiber code or an optical cable, and the optical fibers 12c and 12d in the output side are provided at the same receiving location by the optical fiber code and the optical cable, so that transmitting and receiving of the optical signal are performed.
However, in the conventional optical branching coupler, since a pair of the optical wave guides 11a and 11b is formed on the optical waveguide chip 10, the optical fibers 12a and 12b in the input side are provided at the same transmitting location, and the optical fibers 12c and 12d in the output side are provided at the same receiving location. Due to this, for combining the respective optical signals transmitted from the different locations or for transmitting the optically branched optical signals to the different locations, there must be increased the number of the optical branching couplers in which the optical fibers are connected to the connecting end portion of the input side and the output side, as required.
On the other hand, in a case where the optical fibers are connected by use of an optical connector device, the number of the cores of the optical fibers to be connected is set to be the same, and the connection of both optical fibers are made by use of the connector in which the optical fibers is disposed. In this case, the optical signal sent from the optical fiber in the input side is always transmitted to the optical fiber in the determined output side.
In recent years, there has been considered an optical communication system wherein a multi-core optical fiber is used in an input side and an optical signal is branched and transmitted to the different locations. However, the above-mentioned conventional optical connector cannot deal with such a new type of the optical communication system.